1. Field
Embodiments of the inventive concepts relate to a lithium-air secondary battery and a method of manufacturing the same and, more particularly, to a lithium-air secondary battery having a positive electrode including molybdenum carbide and a method of manufacturing the same.
2. Description of the Related Art
Secondary batteries capable of storing electric energy have been increasingly demanded with the development of portable mobile electronic devices such as smart phones, MP3 players, and tablet personal computers. In particular, lithium-air secondary batteries have been increasingly demanded with the development of electric cars, medium and large energy storage systems, and portable devices requiring a high energy density.
The lithium-air secondary battery may include a lithium negative electrode, a lithium ion conductive electrolyte, and an air electrode in which a reversible electrochemical reaction of oxygen and lithium ions occurs. The lithium-air secondary battery has a high theoretical energy density of 11,140 Wh/kg, and thus it can provide a higher energy density than currently used lithium ion batteries.
In addition, the lithium-air secondary batteries may be cheaper and more environmentally friendly than conventional lithium ion batteries, and stability of the lithium-air secondary batteries may be more than those of the conventional lithium ion batteries. Thus, the lithium-air secondary batteries are being actively researched and developed as power sources for electric cars.
For example, Korean Patent Publication No. 10-2012-0105736 (Application No. 10-2011-0023359, Applicant: Korea Institute Of Science And Technology) discloses a method of manufacturing a carbon-based positive electrode for a lithium-air battery. In this method, a composition which includes a binder resin and carbon powder having a surface area of 500 m2/g to 2000 m2/g and a porosity of 0.5 cm3/g to 5 cm3/g is injected into pores of a porous current collector in order that the carbon-based positive electrode provides optimal pores which smoothly causes an oxidation reaction of lithium.
Carbon used as a positive electrode of the lithium-air secondary battery may have excellent conductivity, a low cost, and a wide surface area. However, if carbon is used alone in the positive electrode, the carbon may be decomposed in charging/discharging processes to cause a side reaction.